EFFECT OF TEMPERATURE ON THE DEGRADATION OF ASCORBIC ACID (VITAMIN C) CONTAINED IN INFANT SUPPLEMENT FLOURS DURING THE PREPARATION OF PORRIDGES

This work concerns the incorporation of Parkia biglobosa pulp and Adansonia digitata pulp (baobab) into infant flours produced by the Togolese Institute for Agricultural Research (ITRA) in order to increase their micronutrient and especially vitamin C content. The 2,6-dichlorophenol-indophenol (DIP) method is then used to determine vitamin C in the prepared porridges of these enriched flours to study the effect of heat or temperature on the degradation of this vitamin C. The results show that the highest destruction of ascorbic acid or vitamin C occurs at temperatures between 85 and 95°C, especially after 10 minutes of cooking time. The initial value of 66.67 mg for 10Nx10 enriched flour decreases to 2.64 mg after 2 minutes cooking time and becomes practically zero after 20 minutes (0.50 mg). As for the enriched 10Ne10 flour, its initial vitamin C value decreases from 67.74 mg to 3.04 mg after 2 minutes of cooking time and then to 0.40 mg after 20 minutes. The study ofthe degradation of vitamin C through a gradual decrease of temperature by cooling the porridges, shows a slightly degradation after 10 minutes cooling at the temperatures between 60 and 80°C. The initial values of 10Nx10 and 10Ne10 flours decrease from 66.67 mg to 52.20 mg and from 67.74 mg to 60.30 mg respectively. From these results, we can conclude that heat destroys almost all the vitamin C contained in the flours during the preparation of the porridges at the temperatures between 80 and 95°C. It becomes necessary to incorporate the baobab pulp rich in vitamin C after the cooking and cooling of the porridges between 60 and 80°C to avoid a total destruction of the vitamin C.